So my dad has a 2000, 2wd, tow package, 4.7l, with 178,300 miles. When towing down the road, it cools fine. Stays right before 210. But once he kicks off the overdrive, it'll go all the way up to 240 and the fan clutch still won't engage. He's had Dodge replace the fan clutch twice and that didn't change anything. After that they said they didn't know what is wrong with it. He switched it to a Hayden and it does the same thing. The tech guy at Hayden said that the ambient air temp isn't getting high enough to cause it to engage. It's 100 degrees outside and the water temp gets to 240, how could the ambient air temp not get high enough??? Any other ideas??? How many cfm is the condenser fan rated for?

 

More of a question than a statement: Could this be a transmission cooling issue that is causing this? My logic is based on the tranny cooling lines going into the radiator. If the tranny fluid was exceptionally hot, it would cause the radiator to get hot and perhaps overheat the truck. Is this possible?

Sorry I'm not helping your particular issue directly.

 

You make a valid point, but if the fan isn't engaging, that would be why it gets to 240 in the first place. Even moving at 60mph, under a load it's going to create a lot of heat.

 

I was thinking tranny issue because that is the changing variable in your situation by switching OD off. It is obviously necessary to switch OD off when towing or risk ruining your tranny.

Consider upgrading the electric fan (what youre referfing to as the condenser fan) to either an aftermarket one or a ford taurus 3.8L electric fan. There are posts all over this forum on the topic. Doing this would eliminate the need for the clutch fan all together. It would replace the stock electric fan. It would be powerful enough to fill all of your airflow needs. I will be doing this in the near future.

Have you checked that the thermostat is opening appropriately? You can just feel the upper radiator hose when the car is at operating temp.